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Can open Firefox XPCOM file is missing. Can't uninstall it either and can't download new exe file. what can I do?

  • 2 replies
  • 10 have this problem
  • 1 view
  • Last reply by cor-el

thehawk
thehawk
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Running Windows Vista. Shut down my PC other day and when I booted up it wouldn't start. Hit the power button again and it started in safe mode and asked me to run a repair program which I did. after that Firefox wouldn't open and I get the "XPCOM is missing" message. everything else works. Tried to uninstall Firefox and can't do that either. the Control panel uninstaller doesn't work and I found the Mozilla Firefox uninstall helper file and that won't run either. I get the Windows display that asks me to Continue or Cancel and when I hit Continue the dialog box just disappears and nothing happens. Also can't download new Firefox exe file. I am running Trend Micro security on on PC.

Running Windows Vista. Shut down my PC other day and when I booted up it wouldn't start. Hit the power button again and it started in safe mode and asked me to run a repair program which I did. after that Firefox wouldn't open and I get the "XPCOM is missing" message. everything else works. Tried to uninstall Firefox and can't do that either. the Control panel uninstaller doesn't work and I found the Mozilla Firefox uninstall helper file and that won't run either. I get the Windows display that asks me to Continue or Cancel and when I hit Continue the dialog box just disappears and nothing happens. Also can't download new Firefox exe file. I am running Trend Micro security on on PC.

Chosen solution

You will have to reinstall, don't worry, because none of your bookmarks, history etc. WILL NOT BE LOST. Note: You might want to print these steps or view them in another browser.

  1. Download the latest Desktop version of Firefox from http://www.mozilla.org and save the setup file to your computer.
  2. After the download finishes, close all Firefox windows (click Exit from the Firefox or File menu).
  3. Delete the Firefox installation folder, which is located in one of these locations, by default:
    • Windows:
      • C:\Program Files\Mozilla Firefox
      • C:\Program Files (x86)\Mozilla Firefox
    • Mac: Delete Firefox from the Applications folder.
    • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
  4. Now, go ahead and reinstall Firefox:
    1. Double-click the downloaded installation file and go through the steps of the installation wizard.
    2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.
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All Replies (2)

kobe
kobe
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Chosen Solution

You will have to reinstall, don't worry, because none of your bookmarks, history etc. WILL NOT BE LOST. Note: You might want to print these steps or view them in another browser.

  1. Download the latest Desktop version of Firefox from http://www.mozilla.org and save the setup file to your computer.
  2. After the download finishes, close all Firefox windows (click Exit from the Firefox or File menu).
  3. Delete the Firefox installation folder, which is located in one of these locations, by default:
    • Windows:
      • C:\Program Files\Mozilla Firefox
      • C:\Program Files (x86)\Mozilla Firefox
    • Mac: Delete Firefox from the Applications folder.
    • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
  4. Now, go ahead and reinstall Firefox:
    1. Double-click the downloaded installation file and go through the steps of the installation wizard.
    2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.
cor-el
cor-el
  • Moderator
  • Top 10 Contributor
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Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) as a test to see if that helps to download the Firefox installer.

You can find the full version of the latest Firefox 24.0 release in all languages and for all Operating Systems here: